If you have OTK Naruto or CS2 Sasuke do their Up Combo followed by their Air Combo and you should have more than enough. If you land all hits for OTK Naruto it will hit 23 times and if you land all of CS2 Sasukes hits you will get a 30 combo
Naruto can get it pretty easy by comboing into his demon windmill jutsu. Do his forward combo and at around 5-7 hits launch the jutsu.
Alternately, anyone who has a "shuriken cloud" as their chakra projectile can use that mid-way through a combo for an extra 14-16 hits on the combo counter. --- There is no situation that cannot be improved by the addition of monkeys, midgets, or pizza or any combination of the three. R.I.P. Mitch Hedberg 3/30/05